The Public Warning System (PWS) provides timely and accurate alerts, warnings and information, regarding disasters and other emergencies. PWS is currently defined in the 3rd generation partnership project (3GPP) without security and provides a framework for regional emergency services such as the Korean Public Alert System (KPAS), European Warning System (EU-ALERT), Commercial Mobile Alert System (CMAS) and Earthquake and Tsunami Warning System (ETWS).
Information contained in a PWS message is text-based and can be delivered at a local or national level in a timely manner. Accordingly PWS messages are useful in providing a basic warning system. However, constraints within the existing standards (e.g. 3GPP) specification and implementation has led to difficulties in supporting richer and visual public safety content since text messages carry only human-readable characters and are of limited size. Examples of richer public safety content include maps with public safety mark-up, images of missing persons, evacuation information, weather warnings, emergency shelter locations, and assembly points etc.
In order to minimize the impact on mobile devices (referred to herein as user equipment or UE), impact on operators' networks, and cost, it is expected that a richer public safety content delivery solution re-use the existing PWS mechanism. Therefore, a means of extending PWS support to include larger binary (non-text based) data in the messages is needed in order to provide richer content in a backwards compatible manner. This richer content needs to be logically related to the legacy PWS messages, which they enhance, and delivered in a timely manner as applicable for the PWS message category (e.g. Presidential vs. Amber Alert).